Microheater

About: Microheater is a research topic. Over the lifetime, 814 publications have been published within this topic receiving 12478 citations.

Capacitive humidity sensor design based on anodic aluminum oxide

Abstract: Capacitive humidity sensors based on anodic aluminum oxide (AAO), a material used as a sensing layer for high sensitivity, were investigated. The AAO film has many nanosized pores, giving it a large surface area for absorbing water vapor. Effects of design factors and heating were investigated. A thick porous layer or big pore diameter increases sensitivity because of increase in contact surface area. An electrode of rectangular spiral-shaped type tends to have a slightly higher hysteresis than the interdigitated type, but the rectangular spiral-shaped type is efficient and sensitive if the hysteresis and nonlinearity are reduced by controlling design factors or heating. Although heating reduced the sensitivity, it improved performance parameters such as nonlinearity, hysteresis, response time and temperature dependence. Also, a porous electrode would show a higher sensitivity than a nonporous electrode because of the larger surface area.

Realization and performance of thin SiO2/SiNx membrane for microheater applications

Abstract: There is considerable interest in thin-film microheaters for decreasing the power consumption in portable applications. In this paper, we present the study of new stacked thin membranes (SiO 2 /SiN 1.2 ) supporting the heating element (polysilicon resistor). The great interest of using SiN 1.2 deposited onto a SiO 2 layer is the improvement in mechanical properties of the membrane, leading to a fabrication yield very close to 100%. Microheaters fabricated with a 1.6 mm × 1.6 mm square and 0.7 μm thick SiO 2 /SiN 1.2 membrane give promising results in terms of power consumption; 230°C is reached with an electrical power of 50 mW.

Improved Selectivity and Sensitivity of Gas Sensing Using a 3D Reduced Graphene Oxide Hydrogel with an Integrated Microheater

Abstract: Low-cost, one-step, and hydrothermal synthesized 3D reduced graphene oxide hydrogel (RGOH) is exploited to fabricate a high performance NO2 and NH3 sensor with an integrated microheater. The sensor can experimentally detect NO2 and NH3 at low concentrations of 200 ppb and 20 ppm, respectively, at room temperature. In addition to accelerating the signal recovery rate by elevating the local silicon substrate temperature, the microheater is exploited for the first time to improve the selectivity of NO2 sensing. Specifically, the sensor response from NH3 can be effectively suppressed by a locally increased temperature, while the sensitivity of detecting NO2 is not significantly affected. This leads to good discrimination between NO2 and NH3. This strategy paves a new avenue to improve the selectivity of gas sensing by using the microheater to raise substrate temperature.

Fast-Response, Sensitivitive and Low-Powered Chemosensors by Fusing Nanostructured Porous Thin Film and IDEs-Microheater Chip

Abstract: Fast-Response, Sensitivitive and Low-Powered Chemosensors by Fusing Nanostructured Porous Thin Film and IDEs-Microheater Chip

Novel cell patterning using microheater-controlled thermoresponsive plasma films

Abstract: A novel approach is reported for cell patterning based on addressable microheaters and a poly(N-isopropyl acrylamide) (pNIPAM) themoresponsive coating. This thermoresponsive coating is created by a radio frequency NIPAM plasma and is denoted as plasma polymerized NIPAM (ppNIPAM). Films of ppNIPAM with a good retention of monomer side-chain functionality are produced using low-power continuous plasma deposition. Cell adhesion and cell detachment tests indicate that the surface switches between adhesive and nonadhesive behaviors as a function of temperature. The use of a photolithographically fabricated microheater array allows the ppNIPAM transition to occur spatially under the control of individual heaters. This localized change in the surface adhesive behavior is used to direct site-specific cell attachment. Patterned adhesion of two types of cells has been visualized on the array through fluorescent markers. Applications for diagnostic devices, cell-based sensors, tissue engineering, and cell transfection are envisioned. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 159–168, 2004